Very Small Aperture Terminal (VSAT) systems are satellite communications systems that serve home and business users. VSAT may be used to provide broadband access to remote customers. VSAT may employ demand-assigned time division multiple access (DA-TDMA) techniques to share satellite bandwidth among remote customers at different sites based on allocation of time slots rather than frequency. Network operators and service providers afford to their VSAT customers a variety of services. These services may include data, voice, and multimedia. Regardless of the type of service, it is desirable to offer customers a certain level of quality of service (QoS). Typically, in order to provide QoS guarantees, packets may be classified into predefined service classes. Terrestrial-based QoS models may apply QoS policies to the classified packets based on a fixed available data rate. In contrast with terrestrial systems, VSAT systems have variable bandwidth that precludes the use of conventional QoS models.